An aeromagnetic measurement device based on NV color center magnetometer

Abstract

The present invention relates to the field of airborne magnetic measurement technology, and particularly to an airborne magnetic measurement device based on an NV - center magnetometer, which includes an aircraft, an NV - center magnetometer, a positioning module, a local storage module, and a mobile power supply; the NV magnetometer is based on the nitrogen - vacancy center quantum effect and can achieve high - sensitivity magnetic field detection at the nT level at room temperature. It does not require the complex temperature control system of traditional optically pumped magnetometers, has lower power consumption and smaller volume, is suitable for lightweight unmanned aerial vehicle platforms. Its multi - axis vector measurement ability can directly obtain three - dimensional magnetic field data, improve the target space resolution accuracy, and has strong anti - electromagnetic interference, being suitable for complex electromagnetic environments. The broadband characteristic supports transient field detection, providing a high - resolution solution for resource exploration and military reconnaissance.

Description

Technical Field

[0001] The present invention relates to the field of airborne magnetic measurement, and particularly to an airborne magnetic measurement device based on an NV - center magnetometer. Background Art

[0002] Airborne magnetic measurement is a geophysical exploration technology based on a flying platform (such as an airplane, a drone) carrying a magnetometer. By collecting geomagnetic field data to analyze the magnetic differences of underground substances, it is widely used in fields such as resource exploration, geological survey, and environmental monitoring. Its core value lies in breaking through the spatio - temporal limitations of traditional ground magnetic measurement and realizing efficient and large - scale acquisition of geological information. In complex terrain areas (such as plateaus, forests, swamps, deserts, etc.), the airborne magnetic technology can quickly cover an area of thousands of square kilometers, and the single - flight efficiency is dozens of times higher than that of manual ground measurement. In addition, airborne magnetic data has a strong ability to identify basement structures, fault zones, and magmatic rock bodies. Especially in the exploration of oil and gas basins, the oil - bearing structures can be indirectly delineated through magnetic anomaly characteristics, providing a key basis for drilling site selection. With the iteration of technology, the application scenarios of airborne magnetics are constantly expanding. For example, it is used for seabed topography inversion in marine geological surveys, locating underwater unexploded ordnance in the military field, and detecting underground relics in archaeological research, showing the potential of multidisciplinary cross - integration.

[0003] However, during the airborne magnetic measurement process, in order to improve the detection ability of shallow targets, drones often adopt a terrain - following flight mode (flight height is less than 50 meters). However, ultra - low - altitude flight is sensitive to terrain undulations and is prone to collision accidents. While increasing the flight height can expand the coverage area, it will cause the attenuation of magnetic field signals and make it difficult to identify shallow weak - magnetic targets. Therefore, the requirements for airborne magnetometers are quite high, and how to improve the sensitivity of airborne magnetometers has always been a problem that needs to be studied. Summary of the Invention

[0004] Therefore, the technical problem to be solved by the present invention is: to design an airborne magnetic measurement device with high measurement sensitivity.

[0005] Based on this, the present invention proposes the following technical solution: An airborne magnetic measurement device based on an NV - center magnetometer, comprising:

[0006] - An aircraft;

[0007] - An NV - center magnetometer, carried on the aircraft, which includes:

[0008] A diamond block containing an ensemble of NV centers;

[0009] A laser polarization module for outputting linearly polarized excitation light, the linearly polarized excitation light is configured to enter the diamond block from the

[120] crystal direction to excite the NV centers to generate photoluminescence, and the polarization direction of the linearly polarized excitation light is sequentially switched between the optimal excitation angles of four groups of NV axes.

[0010] A microwave module, which is used to output working microwaves to the diamond block;

[0011] An optoelectronic detection module, which is used to collect photoluminescence and convert it into magnetic field detection data;

[0012] - A positioning module, which is used for real-time positioning of the aircraft and obtaining synchronous longitude and latitude data;

[0013] - A local storage module, which is used to locally record magnetic field detection data and synchronous longitude and latitude data;

[0014] - A mobile power supply, which is used to supply power to the NV center magnetometer, the positioning module and the local storage module.

[0015] In a preferred design, the NV center magnetometer includes a probe optical fiber, the diamond block is arranged on one end face of the probe optical fiber, and the excitation light output by the laser polarization module enters the diamond block through the probe optical fiber.

[0016] In a preferred design, the probe optical fiber is a single-mode polarization-maintaining optical fiber.

[0017] In a preferred design, the laser polarization module includes a laser and a fiber polarization scrambler, which are connected by another single-mode polarization-maintaining optical fiber. The fiber polarization scrambler is connected to the diamond block through the probe optical fiber. The laser is used to output linearly polarized excitation light, and the fiber polarization scrambler is used to adjust the angle of the linearly polarized excitation light.

[0018] In a preferred design, a power stabilization circuit is further included, which is used to stabilize the laser output power of the laser.

[0019] In a preferred design, the diamond block is single-crystal diamond, which is a cuboid or a cube, its upper surface is perpendicular to the

[001] crystal direction, and one side surface is perpendicular to the

[120] crystal direction.

[0020] In a preferred design, the optoelectronic detection module includes a TIR lens, a filter and a photodetector. The light emitted from the diamond block is collected by the TIR lens, and the collected light is filtered by the filter to filter out the photoluminescence and then collected by the photodetector.

[0021] In a preferred design, the positioning module adopts a GPS positioning module.

[0022] In a preferred design, a magnetic compensation system is further included, which is carried on the aircraft and is used to eliminate the magnetic interference of the aircraft operation on the NV center magnetometer.

[0023] In a preferred design, the outer side of the power motor of the aircraft is coated with an aluminum film.

[0024] The beneficial effects of the non-destructive testing device of the present invention are as follows: The NV magnetometer is based on the nitrogen-vacancy color center quantum effect, and can achieve high-sensitivity magnetic field detection at the nT level at room temperature. It does not require the complex temperature control system of traditional optically pumped magnetometers, has lower power consumption and smaller volume, and is suitable for lightweight drone platforms. Its multi-axis vector measurement ability can directly obtain three-dimensional magnetic field data, improve the target space resolution accuracy, and has strong anti-electromagnetic interference, suitable for complex electromagnetic environments. The broadband characteristic supports transient field detection, providing a high-resolution solution for resource exploration and military reconnaissance. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings of the embodiments of the present invention will be briefly introduced below. Obviously, the drawings described below only relate to some embodiments of the present invention and do not limit the present invention. Among them:

[0026] Figure 1 It is a module diagram of the airborne magnetic measurement device in the embodiment of the present invention.

[0027] Figure 2 It is a schematic diagram of the composition of the NV color center magnetometer in the embodiment of the present invention.

[0028] Figure 3 It is a four-axis distribution diagram of diamond NV color centers.

[0029] Figure 4 It is an example diagram of exciting NV color centers with polarized light in the traditional technology.

[0030] Figure 5 It is an ODMR spectrum with eight peaks.

[0031] Figure 6 It is Figure 2 The enlarged schematic diagram at position A in

[0032] Figure 7 It is a schematic diagram of the TIR lens in the embodiment of the present invention.

[0033] Figure 8 It is the crystal orientation distribution of conventional cubic diamond NV color centers.

[0034] Figure 9 (a) is a top view of a diamond block with the top surface perpendicular to the

[001] crystal orientation.

[0035] Figure 9 (b) is to mark two longitudinal cutting lines along the

[001] crystal orientation on the top surface of the diamond block.

[0036] Figure 9 (c) is to mark two transverse cutting lines along the perpendicular crystal orientation on the top surface of the diamond block after the first cutting.

[0037] Figure 9(d) is the top view of the diamond block for secondary cutting.

[0038] Figure 9 (e) is the three-dimensional view of the diamond block for secondary cutting.

[0039] Reference numerals:

[0040] 1. Diamond block; 2. Laser polarization module; 3. Microwave module; 4. Photoelectric detection module; 5. Probe optical fiber; 21. Laser; 22. Optical fiber polarization scrambler; 23. Single-mode polarization-maintaining optical fiber; 24. Power stabilization circuit; 31. Microwave source; 32. RF transmission line; 33. Antenna; 41. TIR lens; 42. Filter; 43. Photoelectric detector; 411. Light source hole. Detailed implementation manners

[0041] To enable those skilled in the art to better understand the present invention, the present invention will be further described in detail below in conjunction with the detailed implementation manners and the accompanying drawings.

[0042] The terms used in the present invention are those general terms that are currently widely used in the art in consideration of the functions of the present invention. However, these terms may vary according to the intentions of those of ordinary skill in the art, precedents, or new technologies in the art. In addition, specific terms may be selected by the applicant, and in such cases, their detailed meanings will be described in the detailed description of the present invention. Therefore, the terms used in the specification should not be understood as simple names, but based on the meanings of the terms and the overall description of the present invention.

[0043] Referring to Figure 1 , this embodiment provides a airborne magnetic measurement device based on an NV - center magnetometer, including an aircraft, an NV - center magnetometer, a positioning module, a local storage module, and a mobile power supply.

[0044] Among them, the aircraft, with its efficient and flexible characteristics, has become the core carrier for collecting magnetic field data in complex terrains. It can achieve high-resolution detection of shallow weak magnetic targets (such as thin-layer ores) through terrain-following flight (altitude < 50 meters), with its efficiency being dozens of times higher than that of traditional methods, and it can operate safely in high-risk areas (unexploded ammunition, polluted waters). In this example, the DJI Matrice 600M drone is selected as the aircraft. It has powerful power, is equipped with a 6-axis power system, can carry a load of 6 kilograms, and has a maximum takeoff weight of 15.1 kilograms. In terms of its fuselage structure, the M600 adopts a modular design, making assembly and use quick and convenient. The bearing system at the core of the motor has been strictly sealed to prevent corrosion by rainwater and sand and dust. The optimized air-cooling system can effectively reduce the motor temperature. The specially designed protection structure can prevent foreign objects from entering the motor interior, enabling the aircraft to continue operating in harsh environments. The M600 is equipped with 6 independent intelligent batteries, and DJI has customized a battery management system for it. The aircraft can achieve a safe landing in the event of the failure of any one battery. The user can switch any one battery to act on the entire system without having to operate each one individually.

[0045] In this example, the NV color center magnetometer is carried on the aircraft, as shown in the appendix Figure 2 It includes a diamond block 1, a laser polarization module 2, a microwave module 3, and a photoelectric detection module 4. Among them: The diamond block 1 contains an ensemble of NV color centers. The atom pairs composed of the vacancies replacing carbon atoms and nitrogen atoms in the nitrogen-vacancy color centers also have four different orientations, that is, there are four axial directions, as shown in the appendix Figure 3 It shows; The laser polarization module 2 is used to output linearly polarized excitation light. The linearly polarized excitation light is configured to enter the diamond block 1 from the

[120] crystal direction to excite the NV color centers to generate photoluminescence, and the polarization direction of the linearly polarized excitation light is sequentially switched between the optimal excitation angles of the four groups of NV axes; The microwave module 3 is used to output working microwaves to the diamond block 1; The photoelectric detection module 4 is used to collect the photoluminescence and convert it into magnetic field detection data.

[0046] Regarding the significance and function of the linearly polarized excitation light incident from the

[120] crystal direction in this application, further explanations are as follows: The optical transition of the NV color center has clear dipole radiation characteristics. The direction of its dipole moment is fixed along the

[111] crystal direction of the diamond. When the electric field polarization direction of the incident light is parallel to the dipole axis of the NV color center, the excitation efficiency is the highest (∝cos 2 θ, where θ is the angle between the polarization direction and the dipole axis); When the polarization direction is perpendicular to the dipole axis, the excitation efficiency approaches zero. Based on this principle, by optimizing the parallelism between the polarization direction and the dipole axis, the fluorescence difference between different spin states can be amplified (such as the ODMR signal contrast being increased to ~30%), thereby enhancing the sensitivity of spin state detection and further improving the sensitivity of the magnetometer.

[0047] Conventionally, the polarization direction can be made completely parallel to a single NV axis. Based on this method, the magnetometer constructed in this way can obtain excellent measurement sensitivity during non-vector magnetic field measurement. However, in airborne magnetic surveys, vector magnetic fields are essential. To improve the measurement sensitivity as much as possible, it is necessary to improve the measurement accuracy of magnetic field components in all four NV axes. In traditional technologies, as shown in Figure 4 as shown, multiple groups of polarization lenses are distributed around the diamond to achieve parallel or nearly parallel polarization directions with each NV axis. However, this structure is scattered and complex, suitable for use in laboratories. During actual detection, due to the requirements of measurement stability and simple structure, the applicant uses a single-fiber-diamond combined quantum probe for detection.

[0048] For a single-fiber-diamond combined quantum probe, the propagation direction of the laser in the fiber is fixed and unique. It is very necessary to optimize the measurement of the laser polarization direction with the four NV axes in turn in this single laser propagation direction (orthogonal to the polarization direction).

[0049] To achieve the above purpose, in this application, the linearly polarized excitation light enters the diamond from the

[120] crystal orientation. Through derivation and calculation, we know that when the linearly polarized light enters from the

[120] crystal orientation, by adjusting the polarization direction, the minimum angle θ with the four NV color center axes is as follows:

[0050] For NV1 [1, 1, 1] and NV4 [-1, -1, 1]: the minimum angle θ ≈ 51°;

[0051] For NV2 [1, -1, -1] and NV3 [-1, 1, -1]: the minimum angle θ ≈ 15°.

[0052] In this application, the optimal excitation angles of the four groups of NV axes mentioned above refer to the concept of the minimum angle. However, due to the inaccuracy of actual operation and observation, we allow the optimal excitation angle to be close to the minimum angle. In a more general concept, the optimal excitation angle can be set by ourselves based on actual needs. Before detection, we perform a traversal of the polarization direction under a known magnetic field to find the optimal excitation angle.

[0053] As mentioned above, during measurement, it is necessary to sequentially switch between the optimal excitation angles at intervals. Here, a specific explanation is given. In this application, there are four optimal polarization directions corresponding to the optimal excitation angles. During vector measurement, four-axis measurement data at the same position are required. Therefore, it is necessary to sequentially switch the optimal polarization directions one by one in a short time, and the interval time is about 100 μs.

[0054] Under the design of the propagation angle of this linearly polarized excitation light, although the polarization direction is not completely parallel to the NV axis, considering comprehensively, we believe that it also has sufficient measurement sensitivity. When performing airborne magnetic vector measurement, we regularly switch the optimal polarization direction (the polarization direction when the angle with the NV axis reaches the minimum θ), and measure the most accurate results of the magnetic field components of the vector magnetic field in the four NV axes respectively. Finally, the accurate vector magnetic field information is calculated through the magnetic field component data in the four axes; for easy understanding, an analysis of the detection principle is made here. After selecting an optimal polarization direction, a ODMR spectrum as shown in the attachment can theoretically be obtained. Only considering the four peaks on the left, they respectively reflect the magnetic field component information of the four axes of NV1-NV4. If we choose to adjust the polarization for the first time to maximize the measurement performance of the NV1 axis, the corresponding peak on the obtained ODMR spectrum will more accurately reflect the magnitude of the magnetic field component. At this time, we extract and save the magnetic field component information corresponding to the fourth peak on the left. Then we switch the polarization direction, sequentially maximize the excitation of the other three axes for magnetic field measurement, and extract and save the corresponding magnetic field component information. Finally, we will deduce the accurate vector magnetic field information from these four accurate magnetic field component information. Figure 5 In a specific example, as shown in the attachment, the NV color center magnetometer includes a probe optical fiber 5. The diamond block 1 is arranged on one end face of the probe optical fiber 5. The excitation light output by the laser polarization module 2 enters the diamond block 1 through the probe optical fiber 5. Among them, the probe optical fiber is preferably a single-mode polarization-maintaining optical fiber; the laser polarization module includes a laser 21 and an optical fiber polarization scrambler 22, which are connected by another single-mode polarization-maintaining optical fiber 23. The optical fiber polarization scrambler 22 is connected to the diamond block 1 through the probe optical fiber 5. The laser 21 is used to output linearly polarized excitation light, and the optical fiber polarization scrambler 22 is used to adjust the angle of the linearly polarized excitation light. More preferably, it also includes a power stabilization circuit 24, which is used to stabilize the laser output power of the laser 21; in this example, the microwave module 3 includes a microwave source 31, a radio frequency transmission line 32, and an antenna 33 (preferably a microstrip antenna). The antenna 33 is located near the diamond block 1. The microwave signal output by the microwave source 31 is transmitted to the antenna 33 through the radio frequency transmission line 32 and radiated to the diamond block 1 by it; among them, the photoelectric detection module 4 is a photodetector (such as a photodiode) arranged near the diamond block 1.

[0055] In a specific example, as shown in the attachment Figure 2 In a specific example, as shown in the attachment, the NV color center magnetometer includes a probe optical fiber 5. The diamond block 1 is arranged on one end face of the probe optical fiber 5. The excitation light output by the laser polarization module 2 enters the diamond block 1 through the probe optical fiber 5. Among them, the probe optical fiber is preferably a single-mode polarization-maintaining optical fiber; the laser polarization module includes a laser 21 and an optical fiber polarization scrambler 22, which are connected by another single-mode polarization-maintaining optical fiber 23. The optical fiber polarization scrambler 22 is connected to the diamond block 1 through the probe optical fiber 5. The laser 21 is used to output linearly polarized excitation light, and the optical fiber polarization scrambler 22 is used to adjust the angle of the linearly polarized excitation light. More preferably, it also includes a power stabilization circuit 24, which is used to stabilize the laser output power of the laser 21; in this example, the microwave module 3 includes a microwave source 31, a radio frequency transmission line 32, and an antenna 33 (preferably a microstrip antenna). The antenna 33 is located near the diamond block 1. The microwave signal output by the microwave source 31 is transmitted to the antenna 33 through the radio frequency transmission line 32 and radiated to the diamond block 1 by it; among them, the photoelectric detection module 4 is a photodetector (such as a photodiode) arranged near the diamond block 1.

[0056] Before the above-mentioned NV color center magnetometer works, it is necessary to traverse the polarization direction under a known magnetic field to find the optimal polarization direction. The optical fiber polarization scrambler 22 obtains different phase delays of polarization components in orthogonal directions by changing the voltages of multiple independent ferroelectric liquid crystal phase retarders, thereby changing the polarization state of light and obtaining any polarization state and polarization state traversal. The switching time between different polarization states is less than 100μs. We determine the optimal polarization direction by observing the fluorescence signal measurement spectrum and record the polarization scrambler parameters at the corresponding position.

[0057] During aeromagnetic measurement, the linearly polarized excitation light output by the laser 21 enters the fiber scrambler 22 through the single-mode polarization-maintaining fiber 23, and then connects to the probe fiber 5 to finally enter the diamond block 1 from the

[120] crystal direction. During this process, the fiber scrambler 22 realizes the measurement process in four different optimal polarization directions through parameter switching, and obtains and saves four sets of magnetic field component information. Finally, these data are bound with the position information and sent to the host. The host calculates the vector magnetic field information by setting the system, and binds it with the position information for the second time to complete the aeromagnetic measurement.

[0058] In a further design, in order to improve the fluorescence collection efficiency, the attached Figure 6 and Figure 7 As shown, the photoelectric detection module 4 includes a TIR lens 41, a filter 42 and a photodetector 43. The light emitted from the diamond block 1 is collected through the TIR lens 41 (the bottom of the TIR lens 41 includes a light source hole 411, and the diamond block 1 is placed in the light source hole 411). The collected light is filtered out by the filter 42 to remove the photofluorescence and then collected by the photodetector 43. This design can significantly improve the collection rate of the fluorescence signal.

[0059] In the above design, we require that the propagation direction of the excitation light be configured to be incident into the diamond block 1 from the

[120] crystal direction. Conventional diamond blocks containing NV color centers are usually rectangular or cube-shaped, and generally none of their sides are perpendicular to the

[120] crystal direction. Figure 8 As shown, the direction perpendicular to the side surface is generally

[100] crystal direction,

[010] crystal direction or

[001] crystal direction. Obviously, in this case, it is difficult to connect the optical fiber to the diamond block 1 with the

[120] crystal direction. In order to solve this problem, this example also proposes a diamond structure. Specifically, the diamond block 1 is a single crystal diamond, which is a rectangular parallelepiped or a cube, with its upper surface perpendicular to the

[001] crystal direction and one side perpendicular to the

[120] crystal direction. The steps for preparing this diamond structure are exemplarily as follows. Figure 9 As shown:

[0060] 1. Prepare a diamond block containing NV color centers, and use an X-ray diffractometer to determine the

[001] and

[120] crystal directions of the diamond crystal, such asFigure 9 As shown in (a), its top surface is perpendicular to the crystal orientation

[001] , and the crystal orientation

[120] is drawn from the perspective of the top surface as shown by the arrow in the figure;

[0061] 2. Use a laser to scratch a reference line on the surface of the diamond to mark the longitudinal cutting direction, as shown by the dotted line in Attachment Figure 9 (b), and complete the laser cutting along the dotted line;

[0062] 3. Continue to mark the transverse cutting direction, as shown by the dotted line in Attachment Figure 9 (c), and complete the laser cutting along the dotted line;

[0063] 4. Finally, a cuboid diamond block is obtained, whose upper surface is perpendicular to the

[001] crystal orientation, and one side surface is perpendicular to the

[120] crystal orientation, as shown in Attachment Figure 9 (d) and 9(e).

[0064] After preparing the diamond block 1 by the above method, align its side surface with the end face of the single-mode optical fiber, and use optical glue to bond and fix it.

[0065] In this example, the positioning module is used for real-time positioning of the aircraft to obtain synchronous longitude and latitude data; in a specific example, a GPS positioning module, model ATK-1218-BD, can be used. The NV color center magnetometer and the GPS positioning module achieve software synchronization, and the magnetic field data and GPS longitude and latitude data are stored in the local storage module.

[0066] In this example, the local storage module is used for local recording of magnetic field detection data and synchronous longitude and latitude data, and can be connected to a PC host computer for corresponding data processing; in a specific example, the local storage module can adopt an STM32F407ZGT6 main control board, which can expand the GPS positioning module and other functional modules, realize communication with the NV color center magnetometer sensor, and perform software synchronization on the NV color center magnetometer data and GPS data to achieve local storage, while supporting data processing and communication with the host computer.

[0067] In this example, the mobile power supply is used to supply power to the NV color center magnetometer, the positioning module, and the local storage module.

[0068] Considering that the quality of the acquired data in airborne magnetic surveys depends to a large extent on the effectiveness of compensation, and the target magnetic anomaly signal decays with the cube or fourth power of distance. Without good compensation, the signal of the detection target is easily completely masked by the interference of the magnetic field of nearby aircraft. Therefore, in a preferred design, it also includes: a magnetic compensation system, which is carried on the aircraft and is used to eliminate the magnetic interference of the aircraft's operation on the NV color center magnetometer. In a specific example, the AARC51 data acquisition system and the adaptive real-time compensator of RMS Instruments can provide real-time magnetic interference compensation for the aircraft's onboard system, effectively utilizing the high resolution of the high-sensitivity magnetometer, compensating for the effects of permanent magnetism, electromagnetic induction magnetism, and eddy currents, and also eliminating the steering error of the sensor. Without this system, the interference of the power motor is overcome in two ways: one is that the diamond quantum magnetometer probe is suspended in a hard-connected manner at a certain distance from the fuselage, and the other is to consider wrapping the power motor with an aluminum film to weaken the interference of the eddy current field generated during flight.

[0069] In the description of this specification, the descriptions referring to terms such as "one embodiment", "example", "specific example", etc. mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0070] The preferred embodiments of the present invention disclosed above are only used to help explain the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the present invention to the specific embodiments described. Obviously, many modifications and variations can be made according to the content of this specification. The present specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can well understand and utilize the present invention. The present invention is only limited by the claims and their full scope and equivalents.

Claims

1. An aeromagnetic measurement device based on NV color center magnetometer, characterized in that: include: - Aircraft; -NV color center magnetometer, carried on the aircraft, which includes: A diamond block containing an ensemble NV color center; A laser polarization module, for outputting linearly polarized excitation light, wherein the linearly polarized excitation light is configured to enter the diamond block from the [120] crystal direction to excite the NV color center to generate photoluminescence, and the polarization direction of the linearly polarized excitation light is switched in sequence between four groups of optimal excitation angles of the NV axis; A microwave module, used for outputting working microwaves to the diamond block; Photoelectric detection module, used to collect photoluminescence and convert it into magnetic field detection data; - Positioning module, used for real-time positioning of the aircraft and obtaining synchronized longitude and latitude data; -Local storage module, used to locally record magnetic field detection data and synchronize longitude and latitude data; -Mobile power supply, used to power the NV color center magnetometer, positioning module and local storage module.

2. The aeromagnetic measurement device according to claim 1, characterized in that: The NV color center magnetometer comprises a probe optical fiber, the diamond block is arranged on one side end face of the probe optical fiber, and the linearly polarized excitation light output by the laser polarization module enters the diamond block through the probe optical fiber.

3. The aeromagnetic measurement device according to claim 2, characterized in that: The probe optical fiber is a single-mode polarization-maintaining optical fiber.

4. The aeromagnetic measurement device according to claim 3, characterized in that: The laser polarization module includes a laser and an optical fiber polarization scrambler, which are connected by another single-mode polarization-maintaining optical fiber. The optical fiber polarization scrambler is connected to a diamond block via a probe optical fiber. The laser is used to output linearly polarized excitation light, and the optical fiber polarization scrambler is used to adjust the angle of the linearly polarized excitation light.

5. The aeromagnetic measurement device according to claim 4, characterized in that: A power stabilization circuit is also included, which is used to stabilize the laser output power of the laser.

6. The aeromagnetic measurement device according to claim 4, characterized in that: The diamond block is a single crystal diamond, which is a rectangular parallelepiped or a cube, with its upper surface perpendicular to the [001] crystal direction and one side surface perpendicular to the [120] crystal direction.

7. The aeromagnetic measurement device according to claim 1, characterized in that: The photoelectric detection module comprises a TIR lens, a filter and a photoelectric detector. The light emitted from the diamond block is collected by the TIR lens. The collected light is filtered out of the photofluorescence by the filter and then collected by the photoelectric detector.

8. The aeromagnetic measurement device according to claim 1, characterized in that: The positioning module adopts a GPS positioning module.

9. The aeromagnetic measurement device according to claim 1, characterized in that: It also includes: a magnetic compensation system, which is carried on the aircraft and is used to eliminate the magnetic interference of the aircraft operation on the NV color center magnetometer.

10. The aeromagnetic measurement device according to claim 1, characterized in that: The outside of the aircraft's power motor is covered with aluminum film.

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